1. Field of the Invention
The present invention relates to a pawl for a ratchet-type spanner to provide reliable ratcheting.
2. Description of the Related Art
Spanners are the best choice for working in a tight area, yet the backlash is too large. Ratchet-type spanners have been proposed to solve this problem, and FIGS. 7 through 9 of the drawings illustrate a typical design. As illustrated in FIG. 7, the ratchet-type spanner includes a handle 1' with a box end 11' for rotatably receiving a ratchet gear 2' that is mounted between a ring-like cover plate 6' and a ledge 8' and retained in place by a C-clip 7'. A side of the box end 11' is drilled to form a hole 12' that extends along an axis at an angle of .theta. (12.degree..about.18.degree.) with a horizontal axis of the box end 11'. A pawl 3' is mounted in the hole 12' and includes ratchet teeth 31' formed on a side thereof for releasably engaging with teeth 21' of the ratchet gear 2' and a includes compartment 32' defined in the other side thereof. A spring 4' is mounted in the compartment 32' for biasing the pawl 3' to engage with the teeth 21'. A threaded plug 5' is mounted in the hole 12' and engaged with an inner threading 121' of the hole 12'. The plug 5' includes an inner side 51' for retaining the spring 4' and the pawl 3' in place and includes an outer side with a hexagonal recess 52'.
Nevertheless, the position of the plug 5' affects the function of the pawl 3'. Namely, the pawl 3' cannot be effectively engaged with the ratchet gear 2' for ratcheting if the plug 5' is too far from the ratchet gear 2'. On the other hand, the pawl 3' will be stuck with the ratchet gear 2' if the plug 5' is too close to the ratchet gear 2'. Optimal positioning of the plug 5' is time-consuming and very difficult to achieve even by a skilled worker. Assembly cost is accordingly increased. In addition, the threading engagement between the plug 5' and the hole 12' tends to wear after a term of use such that the user often has to bond the plug by adhesive or glue. Use of the spanner becomes more inconvenient. In addition, assembly of the spanner is complicated and expensive, as the cover 6' and C-clip 7' are required. Furthermore, formation of the ledge 8' requires expensive and accurate computer-numeric-control (CNC), which further results in an increase in the cost.
The present invention is intended to provide a pawl for a ratchet-type spanner that mitigates and/or obviates the above problems.